Hand-controlled safety-knife.



NI. CUHRY.

HAND CONTROLLED SAFETY KNIFE.

APPLxcATloN man HIM/24.1916.

132229866., l Patented Apr. 10,1917.

parra sans amari prima.

MALCOLM CURRY, OF HOLYOKE, MASSACHUSETTS, ASSIGNOR TO THE AMERICAN THREAD COMPANY, OIE' NEW YORK, N. Y., .A CORPORATION OF NEW JERSEY.

HAND-CONTROLLED SAFETY-KNIFE.

To all whom t may concern:

Be it known that I, MALCOLM CURRY, a citizen ol .the United States, residing at Holyoke, county of Hampden, State of hilassachusetts, have invented a certain new and useful Invention Relating to Hand- Controlled Safety-Knives, of whichv the following is a full, clear, and exact description.

My invention relates to hand-controlled safety knives, and has for its object to provide a knife having a guard for the cutting` edge, which can be easily controlled by the hand holdingl the knife so as to expose the cutting edge for use independently of the substance to be out.

The following is a description of an embodiment of my invention, reference being had to the accompanyingdrawings, in which- Figure 1 shows in side elevation a knife embodying my invention.

Fig. 2 shows on an enlarged scale a section of the same on the line 2-2 Fig. 1.

Fig. 3 is a Side elevation of a modification.

Fig. ll is a longitudinal section of another modification embodying my invention.

Fig. 5 is a perspective view of the guard shown in Fig. l.

Referring more particularly to the drawings, 1 is a handle. to which a knife blade 2 is rigidly connected, the cutting edge of said knife blade pointing upward. 3 is a vguard composed of sheet metal bent so as to surround a portion of the back edge of the knife, as shown at et in Fig. 2. The guard embraces both sides of the blade and is provided at a point adjacent to the handle with a portion 5 formed by bending over an extension on one side thereof and adapted to be engaged by 'the thumb of the hand holding the knife s0 that pressure thus applied thereto will move the guard so as to expose for use the end portion of the cutting edge of the blade independently of the substance to be cut by the blade. 6 is a spring, one end of which is connected to the handle, while the other end is soldered at 7 to the guard so as to yieldingly support the guard. The spring is bent around a stud 8 on the blade so as to render its action more definite. Pressure of the thumb upon the portion 5 causesthe guard to move relatively to the blade so as to expose the Specification of Letters Patent.

Application led May 24, 1916.

Fai-vented Apr. 10, 1917.

Serial No. 99,480.

end cutting portion of the blade substantially as shown in Fig. 3. When the pressure is released the spring returns the guard to its normal cutting-edge-protecting position. The inner surface of the portion 41 of the guard engages the back of the blade when the guard is in normal position, the surface of the back of the blade and said inner surface at that point constituting limiting stop surfaces for limiting the relative movements of the parts under the action of' the spring 6.

The construction shown in Fig. 3 is similail to that shown in Fig. 1 except that lthe guard is connected to the blade by a pivot 9 and the spring is not soldered to the guard. The result is substantially the same as in the construction of Fig. 1.

In the construction shown in Fig. et, 1() is a handle, to which a blade 11 is Inovably connected at point 12 by a suitable rivet, the cutting edge of the blade pointing upward. Integral with the handle is a projecting portion 13, which constitutes a guard for the cutting edge of the blade. This guard extends over the back of the blade at the point 11, said portion 141 forming a limiting` stop limiting the relative movements of the parts at a point where the blade will be properly protected by the guard. The rear portion of the guard is cut away along the dotted line 15, so that the thumb of the hand holding the knife can be applied to the rear edge of the blade at a point remote from both ends of the cutting edge in Such manner that pressure thereon will force the cutting blade out beyond the guard independently of the substance to be cut so as to expose it for use. The blade is provided with a rearwardly extendingtang 1G, with which a spring 17 carried by the handle engages, which spring retracts the cutting edge of the blade to a position where it is protected by the guard and thus normally tends to hold the cutting edge in protected position.

It will be seen from the foregoing that in Figs. 1 and 2 the guard-member has an opening extending through the front portion thereof, and along the cutting edge of the blade-member to its point, the plane of said blade-member passing through said opening, and is movable to expose the cutting edge of said blade-member in front of said guard-member, and that said guardmember has a surface located in the plane of said blade-member, so as to be intersected thercby,-this portion of the guard-member being in proximity to the handle and projecting further in front of said edge than the portion of the guard-member adjacent to the point of said blade-member and adapted to receive pressure from the thumb of the hand holding the knife, to move said guardmember so that the cutting edge of the bla cle-member is exposed through the opening in the front of said guard-member.

its will be evident to those skilled in the art, my invention permits of various modifications without departing from the spirit thereof or the scope of the appended claims.

lhat I claim is:

1. In a safety knife the combination of a .flat blade-member having a cutting edge along its front portion, a member constituting a guard therefor having an opening extending through the front thereof and along the cutting edge of said blade-member to its point, the plane of said blade-member passing through said opening, one of said members being movable to expose said cutting edge of said blade-member through said opening, an elongated handle adapted to be grasped by the hand and to Which the other of said members is rigidly connected, a spring for returning said movable member to normal position, said movable member having a surface remote from the end of said cutting edge which is farthest from the handle, and located in the plane'of said blade-member, for receiving pressure of the thumb of the hand holding said handle, to move said movable member from normal position, so that said cutting edge of said blade-member is exposed in front of said guard-member.

2. In a. safety knife the combination of an elongated handle adapted to be grasped by the hand, a blade-member projecting from one end thereof and rigidly connected thereto, the front edge of said blade-member having a cutting portion, a guard-member having an opening in the front portion thereof, said opening lying in the plane of said blade-member and extending to the point thereof, said guard-member being movable so as to expose the cutting portion of the front edge of said blade-member through said opening, a spring for returning said guard-member When so moved, the part of said guard-member in proximity to said handle projecting farther in front of said front edge than the part adjacent to the point of said blade-member, so as to have a surface for receiving the pressure of the thumb of the hand holding said handle to move said guard-member, so that the cutting edge of said blade-member projects through the opening in the front of said guardmember.

8. In a safety knife the combination of an elongated handle adapted to be grasped by the hand, a blade-member projecting from one end thereof and rigidly connected thereto, the front edge of said blade-member having a cutting portion, a guard-member having an opening in the front portion thereof, said opening lying in the plane of said blade-member and extending to the point thereof, said guard-member being movable so as to expose the cutting portion of the front edge of said blade-member through' said opening, a spring for returning said guard-member when so moved, the part of said guard-member in proximity to said handle projecting farther in front of said front edge than the part adjacent to the point of said blade-member, and extending over said front edge so as to be intersected by the plane of said blade-member, so as to have a surface for receiving the pressure of the thumb of the hand holding saidy handle to move said guard-member, so that the cutting edge of said blade-member projects through the opening in the front of said guard-member.

MALCOLM CURRY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

